Releasable means for fastening mold parts



Oct. 14, 1958 M. s'. BRusTAD 2,855,645

RELEASABLE MEANS FOR FA-STENING MOLD PARTS Filed June 6, 1957 iw /////////////l/4 IN V EN TOR.

ATTORNEY United States Patent O had RELEASABLE MEANSAIUR FASTENING MOLD yMy invention relates to a pattern loose piece fastener and an objectof my invention is to provide simple and eicient means for releasably fastening together two or more parts of a pattern used in forming a cavity in molding sand for casting metal.

Another object of my invention is to provide means for attaching together two or more pattern parts in such a manner that they can be handled as a single piece and will not move relative to each other while molding sand is being rammed or packed around them in a molding flask but can easily be withdrawn `from the sand one 'at a time without disturbing the sand.

Another object is to provide means for attaching together two separable pattern parts, said means being in the nature of two interlocking latch members embedded in and secured to the respective pattern parts, said latch members being releasable from an interlocked position when the two pattern parts are relatively transversely moved in one direction but securely locking the two pattern parts `against relative linear movement in all other directions.

Other objects of my invention will be apparent from the following description taken in connection with the accompanying drawings.

In the drawings,

Figure l is a sectional view, with parts in elevation, showing two pattern parts disposed within a ask and embedded in molding sand, said pattern parts being attached together by loose piece fastener means constructed in accordance with my invention.

Fig. 2 is 'an inverted sectional View, with parts in elevation, showing the same apparatus that is shown in Fig. l but showing the loose piece fastener devices in disengaged or unfastened relation and showing one of the pattern parts partially drawn out of the sand.

Like reference numerals refer to like parts throughout the several views.

Patterns used for forming, in molding sand, cavities of various shapes and sizes into which metal is poured in casting must be shaped so that they can be removed or drawn out of the molding sand without disturbing the shape of the cavity made in said sand. For this reason it is often necessary to make patterns in several different parts so that these parts can be Withdrawn from the sand one after another. When this is done it is difficult to properly position and support the unattached parts in a molding flask while molding sand is being rammed around them.

My invention provides simple and eliicient means for securely but detachably fastening two or more pattern parts together so they can be handled as one piece and are held immovable relative to each other While sand is being packed around them in a molding flask but are readily detachable from each other by relative transverse movement of the two pattern parts in a predetermined direction thus allowing the pattern parts to be drawn from the sand one after lanother without disturbing the molded sand.

Patented Oct. 14, 1958 "ice In this connection it is to be borne in mind that the usual procedure followed in molding is to support a pattern in a flask with one side uppermost while the sand is being rammed around the pattern and then to invert the pattern and the 'ask end for end before withdrawing the pattern from the sand. This procedure is followed in using my invention.

The drawings show a flask 5 containing molding sand 6 which is packed around a pattern formed of two parts herein referred to as a main pattern part 7 and a loose piece 8. It will be understood that this two part pattern is merely illustrative and that this invention is applicable to patterns of substantially al1 sizes and shapes and which are formed of two or more parts.

This invention comprises a bolt receiving fitting 9 installed Within a suitably shaped cavity 10 in one of the pattern parts, such as the part 7, and a bolt carrying fitting 11 installed in a cavity 12 in the other part 8.

Preferably the two cavities 10 and 12 in the respective pattern parts 7 and 8 are made with a boring tool by first temporarily securing the loose piece 8 on the main pattern part 7 in the proper position, then boring through the loose piece 8 and into the main part 7 to form the cavities 10 and 12 and then detaching the loose piece 8.

, ing the loose piece S to the main pattern part 7 for boring purposes. After the cavity 10 has been bored in the main pattern part 7, an inclined channel or groove 13 extending from said cavity 10 outward is formed in the face of said main pattern part. This inclined groove can be formed by chiseling. The inclined groove 13 is located so that it will extend radially toward the end of the pattern part 7 which is uppermost at the time sand is being packed around the pattern and which is lowermost at the time the pattern part 7 is being withdrawn from the sand, it being understood that the flask containing the sand and pattern is inverted after introducing the sand and before withdrawing the pattern.

The bolt receiving fitting 9 includes a cylindrical inner end part which fits snugly within the cavity 10. The outer end of this fitting 9 has an inclined cam member 14 extending sidewise therefrom and said outer end is provided with a bolt head receiving recess 15. A bolt head engaging flange 16, having a U-shaped notch 17 therein overhangs part of the bolt head receiving recess 15 at a location substantially diametn'cally opposite to the inclined cam member 14. A screw 18 can be used to secure the bolt receiving fitting 9 to the main pattern part 7. The inclined cam member 14 of the bolt receiving fitting ts within the inclined groove 13 of the pattern part 7.

The bolt carrying fitting 11 preferably is externally of cylndrical shape and has an external thread 19 so that it can be secured to the loose piece 8 by threading it into the same. Obviously the thread 19 can be omitted and the fitting 11 pressed or cemented or otherwise secured within the cavity 12. When the thread 11 is used, tool receiving notches 19 are provided in an end of the fitting 11 to facilitate installation and removal of said fitting. A bolt member comprising a cylindrical part 20 of larger size, a shank 21 protruding axially from an end of said larger part 20 and a head 22 on said shank is carried by and recipro-cably movable in said fitting 11. The fitting 11 has an end wall 23 provided with an opening 24. A stop bolt 25 extends through the opening 24 and is threaded in to or otherwise secured to the larger bolt part 20. A -compression spring 26 is interposed between the larger bolt part 20 and the end wall 23 of the fitting 11 and yieldingly urges the bolt member 20, 21, 22 outwardly into the position in which it is shown in Fig. l, Yieldingly holding the bolt 3 member 20, 21, 22 outwardly in the Fig. l position facilitates engaging or interlocking the two parts of this device together. Other means capable of exerting a yielding outward pressure on the bolt member can be used in place of the spring 26. For instance, permanent magnet means can be used for this purpose.

A plug type closure member 27 can be provided in the outer end of the cavity 12 in pattern part 8 to exclude molding sand from said cavity 12.

In the use of a pattern having two or more parts provided with my fittings, the pattern parts are secured together by engaging the head 22 and shank 21 of the fitting carried by one part within the recess 15 and notch 17 respectively of the fitting carried Iby the other part. This fastens the pattern parts together so they can not be moved relative to each other in any linear direction except in the one relatively transverse direction required to detach the bolt head 22 and shank 21 from the notched flange 16. The pattern with parts thus fastened together is placed in a flask 5 which rests on a dat support 4 in the position shown in Fig. l, the open side of the notch 17 being uppermost in this position. With the pattern thus positioned the sand can be packed around it without relative movement of the parts of the pattern. After the sand has been packed around the pattern and is level with the top of the iask 5 a board or at plate is placed on the top of said flask and the same is inverted. The pattern part 7 is then lifted straight up in the manner shown in Fig. 2. As this part 7 is moved upwardly the notched shoulder 16 is first disengaged from the bolt head 22 and the cam member 14 then presses the bolt head, together with parts 2l and 20 into the housing 11 as the pattern part 7 is drawn out of the sand. The smaller pattern part S can then be drawn out of the sand without disturbing the sand and with the bolt head 22 functioning as a part on which a pull can be exerted.

The foregoing description and accompanying drawings clearly disclose a preferred embodiment of my invention but it will be understood that this disclosure is merely illustrative and that changes may be made within the scope of the following claims.

l claim:

l. Releasable means for attaching together two pattern parts used in making a sand mold for casting, comprising a bolt carrying fitting embedded in one o said pattern parts; a bolt supported for longitudinal movement by said bolt carrying fitting; a head on said bolt; means yieldingly urging said bolt outwardly; a bolt receiving fitting embedded in the other pattern part; and a shoulder rigid with said other bolt receiving `tting, said shoulder having a notch narrower than the distance across said bolt head receiving said bolt, said notch providing releasing of said bolt in response to relative transverse movement of said two patterns parts in one direction and locking the two pattern parts against relative linear movement in all other directions.

2.A The apparatus as claimed in claim l in which an inclined cam is rigid with the bolt receiving fitting and positioned adjacent to and opposite the notch in said shoulder, whereby the bolt head will contact the cam and the bolt and bolt head will be moved clear of the bolt receiving receptacle when the two parts of the pattern are relatively transversely moved in disengaging the bolt from the notch in the shoulder.

3. ln releasable means for fastening together two parts of a pattern used in making sand molds for casting, each ot said pattern parts having an opening therein and said openings registering when the two pattern parts are properly positioned relative to each other; a bolt carrying fitting secured in the `opening in one of said parts; a bolt member supported for longitudinal movement in said bolt carrying fitting; means limiting outward movement of said bolt member in said fitting; a shank on the outer end of said bolt mem-ber; a head of larger diameter than said shank rigid with saidshank; a spring yieldingly urging said bolt member outwardly; a bolt receiving fitting disposed in the 4opening in the other pattern part; shoulder means rigid with said bolt receiving fitting, said shoulder means having a U-shaped notch therein capable of receiving said shank with the shoulder means positioned between the bolt head and the bolt member, whereby relative transverse movement of the two pattern parts in one direction is provided and movement of said two pattern parts in all other linear directions is prevented; and an inclined -cam carried by said ybolt receiving fitting and positioned adjacent to and opposite to the notch in said shoulder means, said cam contacting the bolt head and moving the same clear of the bolt receiving receptacle when the two pattern parts are relatively transversely moved in disengaging the bolt head from the shoulder means.

References Cited in the lile of this patent UNITED STATES PATENTS 1,398,573 Reinl Nov. 29, l92l FOREIGN PATENTS 246,092 Germany Apr. 24, 1912 

